Maleimide derivatives as plant growth regulators

ABSTRACT

COVERS MALEIMIDE DERIVATIVES HAVING THE FOLLOWING GENERAL FORMULA:   1-R&#39;&#39;,3-(R-O-),4-R&#34;-3-PYRROLINE-2,5-DIONE   WHERE R IS SELECTED FROM THE GROUP CONSISTING OF ALKYL, BENZYL, NAPHTHYL, PHENYL, AND SUBSTITUTED PHENYL, R&#39;&#39; IS SELECTED FROM THE GROUP CONSISTING OF HYDROGEN, PHENYL AND SUBSTITUTED PHENYL AND R&#34; IS SELECTED FROM THE GROUP CONSISTING OF HALO AND RO. ALSO COVERS THE METHOD OF EMPLOYING THE JUST DESCRIBED DERIVATIVES AS PLANT GROWTH REGULATORS SPECIFICALLY, COVERS THE METHOD OF THEIR USE AS HERBICIDES.

United States Patent O 3,816,451 MALEIMIDE DERIVATIVES AS PLANT GROWTHREGULATORS Aldo Joseph Crovetti, Lake Forest, and Donald Murl Lynch,Waukegan, 111., assignors to Abbott Laboratories, North Chicago, Ill. NoDrawing. Filed Nov. 2, 1971, Ser. No. 199,393 Int. Cl. C07d 27/18 US.Cl. 260-326.5 FM 21 Claims ABSTRACT OF THE DISCLOSURE Covers maleimidederivatives having the following general formula:

BOA

where R is selected from the group consisting of alkyl, benzyl,naphthyl, phenyl, and substituted phenyl, R' is selected from the groupconsisting of hydrogen, phenyl and substituted phenyl and R" is selectedfrom the group consisting of halo and R0.

Also covers the method of employing the just described derivatives asplant growth regulators. Specifically, covers the method of their use asherbicides.

BACKGROUND OF THE INVENTION Considerable research effort has beenexpended in developing compounds which are useful in influencing thegrowth and development of a wide variety of plants. One of the primaryaims in such endeavors is to develop a series of compounds which has awide spectrum of activity. For example, continuing efforts are beingcarried out to synthesize compounds, which on one hand can beneficiateplants, and on the other hand can eradicate undesirable plant species.Such benefication or eradication will be dependant upon the type ofplant treated, dosages employed, and other factors. Thus, as an exampleit would be a considerable advance in the art if a series of compoundswere discovered which is useful as herbicides to destroy unwanted weeds,and likewise could benefit useful plants by regulating growth.

It therefore becomes object of the invention to provide a novel class ofcompounds which influence the growth and development of a wide varietyof plant species.

A more specific object of the invention is to provide the above seriesof compounds which exhibit herbicidal activity with respect to noxiousweeds.

Other objects will appear hereinafter.

SUMMARY OF THE INVENTION In accordance with the invention a new class ofmaleimide compounds has been discovered. These maleimide' derivativeshave the following general formula:

where R is selected from the group consisting of alkyl, benzyl,naphthyl, phenyl, and substituted phenyl, R is selected from the groupconsisting of hydrogen, phenyl and substituted phenyl and R" is selectedfrom the group consisting of halo and R0.

3,816,451 Patented June 11., 1974 ice The invention here is alsoconcerned with the use of the above compounds as plant growthregulators. More specifically, the above compounds can be used toeradicate noxious weeds by application thereof.

DETAILED DESCRIPTION OF THE INVENTION In more detail the compounds justdescribed in a preferred embodiment have the following structuralformula:

utility as herbicides are 2-alkyl or aryl-oxy-3-chloromaleimides havingthe following general structural formula:

I l V wherein R is selected from the group consisting of alkyl, phenyl,substituted phenyl, naphthyl, and benzyl, and R is selected from thegroup consisting of hydrogen, phenyl and substituted phenyl.

Yet another preferred class of compounds falling within the scope of theinvention have the following general structural formula:

R-O I wherein R is selected from a group consisting of alkyl, phenyl,substituted phenyl and benzyl.

The 2-alkyl or aryl-oxy-3-chloro-N-phenylmaleimides are prepared byreacting an alcoholic salt such as the sodium salt of phenol withN-phenyl-dichloromaleimide in a mole to mole ratio. The followinggeneral reaction sequence and procedure is typical here.

( solvent ROE NaH RONB To a stirred suspension of sodium hydride in asolvent such as dioxane is added an alcohol such as phenol. A slightexcess of sodium hydride is normally employed. The

resultant, salt is then added in a mole to mole ratio to N-phenyl-dichloromaleimide solubilized in a solvent such as dioxane. Themixture is then stirred at room temperature overnight, concentratedunder vacuum, and diluted with water. If the resultant product is solidit may be remole) in 50 ml. of dioxane was added dropwise to 10.8 g.(0.084 mole) of p-chlorophenol dissolved in 150 ml. of dioxane, over aperiod of 50 minutes. The mixture was stirred for 15 minutes and thenadded dropwise over a period of 40 minutes with stirring to 20.0 g.(0.083 mole) moved by filtration, washing with water and recrystalliza-5 of 'N-phenyldichloromaleimide in 100 m1. of dioxane. The tion. vIf anoil in obtained the aqueous phase is normally mixture was stirred atroom temperature over night, condecanted and the product dissolved inchloroform, washed centrated in vacuo, and then diluted with water. Thisgave with water and dried over a dessicant such as magnesium a crude,tan solid that was removed by filtration and sulfate. Thereafter, thesolvent is evaporated and the reslrecrystallized from 95% ethanol togive 15.19 g. of light due triturated under ether to give a solid thatmay be yellow crystals having a melting point of 137-140 C.recrystallized from a number of solvents such as benzene, The abovecompound had a formula of C H Cl NO hexane, ethanol, ether, etc. andanalyzed as follows:

To prepare the 2,3-bis(aryloxy)-N-phenyl-maleimides the same procedureis employed as just described with Percent the exception that 2 moles ofsodium hydride and 2 moles Carbon Hydrogen Chlorine Nitrogen of alcoholare employed per mole of 1m1de. Found 57 53 2 70 21 14 4 22 EXAMPLE ICSICUIlQt BC IIIIIIII 57151 2172 21122 4: 19

2-chloro-3phenogymaleimidegnd 2-chloro-3- EXAMPLE 111 me ox ma e1m1 e y2-chloro-3-(2,4-d1chlorophenoxy)-N-phenylmale1m1de To a stl-rredlce-cople-d sphmon of 1244 (0075 To a stirred suspension of 3 82 g of57% sodium mole) of dichloromalelmlde 1n 100 ml. of methanol was h 1 hadded dropwise over a period of 1% hours a solution of e1 lsperswq (2-18Sedmm 0-091 7.05 g. 0.075 mole) of phenol and 3.0 g. 0.075 equiv- 25 1 22 3 i ggj frg g g z 5 alent of sodium h droxide in 100 ml. of methanol.The Perle 0 one moe 1 mixtlire was allowe d to come to room temperatureoverehlerophenel dissolved f 100 of diexane- T i night with Stirring. TSohltion was then diluted with ture was st1rred for 15 mrngtes and addeddgogwlse while 500 ml. of water ac1d1fied with 10% hydrochloric acid andSurfing ever a Period of 0 P e 2 (0-083 chilled to 4' C. This gave 1.82g. of a solid product havmole) of N'phenyldlehleremalemlde 100 of ing amelting point of 114-116 C. Recrystallization from e The mixture fStirred at e teIPPerature of benzene-'Shellysolve B alforded 1.35 g. r2-chloro-3- 5322 g fi g z ig g fi Wflth z fig fig amber crystals havmg ameltmg tchlore ff fui ext ract 'w e i v zisl l efi wi tll w ter dl ie dover p01nt o Concentration of the filtrate from the above with chillingg 3:3 a g g gf h'ft f d to 4 C. gave 4.43 g. of crude solid.Crystallization from e er gave a 1 e 1 a mixture of benzene andSkellysolve B afforded 1.89 g. 3x21 5233]; 1t t iog ffi c of of producthaving a melting point of 163-165 C. Re- 1 a me mg e crystallizationfrom benzene gave 2-chloro-3-methoxy- 40 The above eempeund havmg theformula w s a a maleimide as pale yellow crystals having a melting pointanalyzed as followsof 165-167 C.

The 2-chloro-3-phenoxymaleimide having the formula Percent C H ClNO wasthen analyzed as follows: Carbon Hydroge Chlorine Nitrogen Found. 62.221.95 29. 39 3. 81 Percent Calculated. 52, 13 2. 19 28. 86 3. 80

Carbon Hydrogen Chlorine Nitrogen Found 53 83 2 74 16 18 6 23 A numberof other 2-alkyl or ary1-oxy-3-chloromalecdenn'tiililiiiiiiiiii 531712111 161 85 61 26 imides were p p according to the j described Pcedures. These compounds have the following general The2-chloro-3-methoxymaleimide having the formula c u a Ormulai C H ,CINOwas analyzed as follows: 0 Percent R 0 I Carbon Hydrogen ChlorineNitrogen 55 N RI Found. 37.31 2.44 21.91 8.78 01 Calculated 37.17 2.5021. 95 8.67

EXAMPLE (II where R is selected from the rou cons'stin of 1 k 1 -chlo-3- hl o -N-h g P 1 g a Y, 2 (4-6 w Xy) P enylmalelmxd? napthyl,phenyl, substituted phenyl and benzyl, and R is i f suspenslon 0f gof57% SOdlum selected from the group consisting of hydrogen, phenylhydride 011 dlsperslon (2.18 g. sodium hydride, 0.091 and substitutedphenyl.

TABLE I Percent MP e t Carbon Hydrogen Chlorine Nitrogen R '0'. yieldFormula Found Calcd. Found Calcd. Found Calcd. Found Cnlcd.

Ph 130-132 46 o H clNo 63.90 64.12 3-C1Ph no 111414 66 oifinenno. 51.5657. 2.28 333 tit? $1.33 if? if; 2-C10H7 Ph 162-164 48 CzoHnOlNOs 68.68.67 3.39 3.46 9.66 10.14 4.06 4.01 4-CH9SPh P11 127-129 74C17H12C1N09S 5s. 62 59.04 3.31 3.50 10. 23 10.25 4.05 4.05 VIII3-CHo,4CHaSPh Ph 134-136 75 Cm uClNOaS 59.99 60.08 3.92 3.92 9. 76 9.853 84 3.89 IX P110111 Ph 41 64.76 65.08 3. 37 3.86 11. 4.47

5 EXAMPLE x 2,3-bis (4-chloro-2-methylphenoxy)-N- phenylmaleimide To astirred suspension of 3.82 g. of 57% sodium hydride Oil dispersion -091mole) in 50 5 the soil treatment method application is used, it isnecesof dioxane was added dropwise, over a period of 1% sary to mix theactive ingredient with the soil, place hours, 111016) 015 y p the activechemical in the root zone or otherwise proin 100 ml. of dioxane. Theslurry was stirred for 15 vide for the plant roots to contact thechemical. Thus, minutes and added rapidly to a stirred suspension of 10the maleimide derivatives may be applied to any of the 10.0 g. (0.041mole) of N-phenyldichloromaleimide in just-mentioned places, as well asany other application 100 ml. of dioxane. The mixture was stirredovernight, area of situs of the plant which will affect the plantconcentrated in vacuo, and diluted with water. The mixso treated. turewas stirred until crystallization occurred, then The active ingredientmay be utilized in diverse formufiltered, and the solid washed withwater. Recrystallizalations, including the adjuvants and carriersnormally emtion from 95% ethanol gave 9.35 g. of crude solid whichployed for facilitating the dispersion of active ingredients was furtherrecrystallized to give 7.68 g. of yellowishfor agriculturalapplications, recognizing a known fact green crystals having a meltingpoint of 124l26 C. that the dosage, formulation, mode of application ofa The above compound which had a formula of chemical agent and othervariables may affect its activity in any given application. Thus, thenst-described male- CMHHCIZNO imide derivatives may be formulated as asolution or diswas then analyzed as follows: persion, in aqueous ornon-aqueous media, as a powdery Percent dust, as a wettable powder, asan emulsifiable concentrate, as a granule, or as any of several otherknown Carbm Hydmge chlm'me Nitmgen types of formulations, depending onthe desired mode of Found 63.68 3.78 14.44 3.13 application. Thesegrowth regulatory compositions may Calculated- 63-45 15-51 be applied assprays, dips, dust, or granules to the plant EXAMPLE XI situs in whichgrowth regulation is desired. These formulations may contain as littleas 0.0005% or as much as 2'3b1S(4'mtrophenoxy)'Nphenylmalelmlde 95% ormore by weight of active ingredient, and ap- To a stirred suspension of7.65 g. of 57% sodium plications may be at rates equivalent to less than2 to hydride oil dispersion (4.36 g., 0.182 mole) in 100 ml. Over 600lbs/acre, depending upon the desired effect of dimethylsulfoxide wasadded dropwise 23.2 g. (0.167 upon plants so treated. mole) of4-nitrophenol dissolved in 100 ml. of dimethyl- In order to providecompositions in the form of dust, lfoxid r a period f 1 ho r nd minutes,The 35 high-strength concentrates, granules, pellets, water-dismixt rwas tirr d for 15 minute and add d dropwise persible powders, aqueoussolutions, dispersions, or emulwith stirring to a suspension of 20.0 g.(0.083 mole) of sions and solutions or dispersions in organic liquids,N-phenyldichloroma'leimide in 100 ml. of dimethylsulthe carrier ordiluent agent in such formulations may foxide, over a period of 1%hours. The mixture was be a finely divided Solid, an Organic liquid,Water, a stirred and then poured into ice water. The mixture was 40wetting agent, a dispersing agent, or emulsifying agent, th f h ti d f20 in t d filt d ith or any suitable combination of these. Generally,when suction. The damp solid was dried in vacuo to yield 35.5 liquidsand wettable Powders are P p a Conditiong. of a dark yellow solid.Recrystallization from chlorog agent C mp is ng One or moresurface-active agents form afforded 22.81 g. of tan crystals having amelting or surfactants is present in amounts sufiicient to render pointof 203 2()5 a given composition containing the active compounds Theabove compound had a formula of C H N O readily dispersible in Water inand analyzed as follows: The surface active agent used in the inventionhere can be a wetting, dispersing or emulsifying agent which willPercent assist dispersion of the compound. The surface-active CarbonHydrogen Nitrogen agent or surfactant can include such anionic, cationicand Fouml 5 ,79 3 02 9 35 non'ionic ge ts s a e heretofore beengenerally em- Clalwlated- 7 9 ployed in plant control compositions ofsimilar type, s it- A number of other maleimide derivatives were madeable surface-active agents are set forth, for example, in according tothe procedures of Example Nos. 10 and 11. Detergents and Emulslfiers1971 Annula by John These compounds have the following generalstructural Mccutcheon formula: general less than 10% by weight of thesurface- 0 active agent W111 be used in compositions of this invention,and ordinarily the amount of surface-active agent will range from 1-5%but may even be less than 1% Q by weight.

Additional surface-active agents can be added to the formulations toincrease the ratio of surfactantzactive ingredient up to as high as 5:1by weight. Such composiwherein R is selected from a group consisting ofphenyl tions may have a greater biological effectiveness than can andsubstituted phenyl. be expected from a consideration of the activity ofthe TABLE II Percent Carbon Hydrogen Chlorine Nitrogen Example M.P.Percent number R yield Formula Found Oalcd. Found Calcd. Found Caled.Found Calcd.

XII Ph 164-166 40 CzzH15NO4 74.07 73.94 4.24 4.23 4.08 3,92 XIII 4-01Ph214-216 63 ozznnonNoi 62.46 61.99 3.02 3.07 16.12 16.64 3.36 3.29 XIVB-ClPh 132-134 41 CzzH1aU1zNO4 62.15 61.99 3.01 3.07 16.67 16.64 3.343.29 XV 4-CHiSPh 163466 65 CZJHIDNO4S2 63.80 64.12 4.27 4.26 3.02 3,12XVI 3-CH=,4-CH SPh 177-179 62 CZBH2KNO4SB 65.08 65.38 4.77 4.85 2.89 2.93

Application of the just described maleimide derivatives may be madeemploying the procedures normally used for treatment of the plant situsincluding dip or soak treatments of tubers, bulbs, or cuttings, forexample, as well as foliar, bark or stem, or soil application. Whencomponents used separately. When used at higher rates, it is preferredthat the surfactant be present in the arnge of one-fifth to five partssurfactant for each one part of active agent.

Wettable powders: Wettable powders are water-dispersible compositionscontaining the active mtaerial, an inert solid extender, and one of moresurfactants to provide rapid wetting and prevent heavy flocculation whensuspended in water.

The inert extenders which are preferred for use in the wettable powdersof this invention containing the active compounds are of mineral origin.

The classes of extenders suitable for the wettable powder formulationsof this invention are the natural clays, diatomaceous earth, andsynthetic mineral fillers derived from silica and silicate. Mostpreferred fillers for this invention are kaolinites, attapulgite clay,montmorillonite clays, synthetic silicas, synthetic magnesium silicateand calcium sulfate dihydrate.

Among the more preferred surfactants are the non-ionic and anionictypes, and those most suitable for the prep aration of the dry, wettableproducts of this invention are solid forms of compounds known to the artas wetters and dispersants. Occasionally a liquid, non-ionic compoundclassified primarily as an emulsifier may serve as both wetter anddispersant.

Most preferred wetting agents are alkylbenzene and alkylnaphthalenesulfonates, sulfated fatty alcohols, amines or acid amides, long chainacid esters of sodium isethionate, esters of sodium sulfosuccinate,sulfated or sulfonated fatty acid esters, petroleum sulfonates,sulfonated vegetable oils, and ditertiary acetylenic glycols. Preferreddispersants are methyl cellulose, polyvinyl alcohol, lignin sulfonates,polymeric alkylnaphthalene sulfonates, sodium naphthalene sulfonates,polymethylene bis-napthalene sulfonate, and sodium-N-methyl-N- (longchain acid) taurates.

Wetting and dispersing agents in these preferred wettable powdercompositions of the invention are usually present at concentrations offrom about 0.5 weight percent to weight percent. The inert extender thancompleted the formulation. Where needed, 0.1 weight percent to 1.0Weight percent of the extender may be replaced by a corrosion inhibitoror an anti-foaming agent or both.

Thus, wettable powder formulations of the invention will contain fromabout 25 to 90 weight percent active material, from 0.5 to 2.0 percentwetting agent, from 0.25 to 5.0 weight percent dispersant, and from 9.25to 74.25 weight percent inert extender, as these terms are describedabove.

When the wettable powder contains a corrosion inhibitor or ananti-foaming agent or both, the corrosion inhibitor will not exceedabout 1 percent of the composition, and the anti-foaming agent will notexceed 0.5 percent by weight of the composition, both replacingequivalent amounts of the inert extender.

High-strength compositions and aqueous suspension concentrates:High-strength compositions generally consist of 90 to 99.5 percentactive ingredient and 0.5 to percent of a liquid or solid surfactantsuch as those described in Detergents and Emulsifiers 1971 Annual byJohn W. McCutcheon, Inc. Such high-strength compositions can often beused in a manner similar to the wettable powders but they are alsosuitable for further formulation.

The aqueous suspension concentrates are prepared by mixing together andsand grinding an aqueous slurry of water-insoluble active ingredient inthe presence of dispersing agents until a concentrated aqueous slurry isobtained in Which the particles of active ingredient are substantiallyall below 5 microns in size. This concentrated aqueous suspension ischaracterized by its extremely small particle size so that upon dilutingand spraying, a very uniform coverage is obtained.

These just-described aqueous suspension concentrates will contain from15 to 40% of active ingredient, from 45 to 70% water, with the remaindermade up of surfactants, corrosion inhibitors and suspending agents.

Suspensions in organic liquids can be prepared in a similar manner suchas by replacing the water with mineral oil.

Dusts: Dusts are dense powder compositions which are intended forapplication in dry form. Dusts are characterized by their free-flowingand rapid settling properties so that they are not readily windborn toareas where their presence is not desired. They contain primarily anactive ingredient and a dense, free-flowing, solid extender. Theirperformance is sometimes aided by the inclusion of a wetting agent, andconvenience in manufacture frequently demands the inclusion of an inertabsorptive grinding aid.

The wettable powder as described above can also be used in thepreparation of dusts. While such wettable powders can be used directlyin dust form, it is more advantageous to dilute them by blending withthe dense dust diluent. In this manner, dispersing agents, corrosioninhibitors, and antifoam agents may also be found as component of adust.

Thus, the dust compositions of this invention will comprise from about 5to 20 weight percent active ingredient, 5 to 25 weight percent filler, Oto 1.0 weight percent wetting agent and from about 30 to weight percentdense, free-flowing extender, as these terms are used herein. Such dustformulations can contain, in addition, minor amounts of dispersants,corrosion inhibitors, and anti-foam agents derived from the wettablepowders used to make the dust.

Emulsifiable oils: Emulsifiable oils are usually solutions of activematerial in non-water miscible solvents together with a surfactant.

For the compounds of this invention, emulsifiable oils can be made bymixing the active ingredient with a solvent and surfactant. Suitablesolvents for the compound of this invention are chlorinated solvents,non-water miscible ethers, esters, or ketones alone or in admixture witharomatic hydrocarbons. Suitable surfactants are those ionic or non-ionicagents known to the art as emulsifying agents.

Emulsifying agents most suitable for the emulsifiable oil compositionsof this invention are long-chain alkyl or mercaptan polyethoxy alcohols,alkylaryl polyethoxy alcohols, sorbitan fatty acid esters,polyoxyethylene ethers with sorbitan fatty esters, polyethylene glycolesters with fatty rosin acids, fatty alkylol amide condensates, calciumand amine salts of fatty alcohol sulfates, oil soluble petroleumsulfonates or, preferably mixtures of these emulsifying agents. Suchemulsifying agents will comprise from about 1 to 10 weight percent ofthe total composition. As described above, however, up to 5 parts ofemulsifying agent for each part of active ingredient can be used.

Thus, emulsifiable oil compositions of the present invention willconsist of from about 10 to 50 weight percent active ingredient, about40 to 82% solvents, and about 1 to 10 weight percent emulsifier, asthese terms are defined and used above.

In some instances the oil solution may be intended merely for extentionwith other oils, and in this instance, the emulsifying agent may beomitted and may be replaced by additional solvent.

Granules and pellets: Granules and pellets are physically stable,particulate compositions containing a compound of this invention whichadheres to or is distributed through a basic matrix of a coherent, inertcarrier with microscopic dimensions. In order to aid leaching of theactive ingredient from the granule or pellet, a surfactant can bepresent.

The inert carrier is preferably of mineral origin, and suitable carriersare natural clays, some pyrophyllites and vermiculite. Suitable settingagents are anionic or non-ionic.

For the granule compositions of this invention, most suitable carriersare of two types. The first are porous, absorptive pre-formed granules,such as pre-formed and screened granular attapulgite or heat expanded,granular, screened vermiculite. On either of these, a solution of theactive agent can be sprayed and will be absorbed at concentrations up to25 weight percent of the total weight. The second, which are alsosuitable for pellets, are initially powdered kaolin clays hydratedattapulgite or bentonite clays in the form of sodium, calcium, ormagnesium bentonites. Water-soluble salts such as sodium salts may alsobe present to aid in the disintegration of the granules or pellets inthe presence of moisture. These ingredients are blended with the activecomponents to give mixtures that are granulated or pelleted, followed bydrying to yield formulations with the active component distributeduniformly throughout the mass. Such granules or pellets can also be madewith 25 to 30 weight percent active component but more frequently aconcentration of about weight percent is desired for optimumdistribution. The granular compositions of this invention are mostuseful in a size range of 30 mesh.

The most suitable wetting agent for the granular compositions of thisinvention depend upon the type of granule used. When pre-formed granulesare sprayed with active material in liquid form, the most suitablewetting agents are non-ionic, liquid wetters miscible with the solvent.These are, more generally known to the art as emulsifiers and comprisealkylaryl polyether alcohols, alkyl polyether alcohols, polyoxyethylenesorbitan fatty acid esters, polyethylene glycol esters with fatty orrosin acids, fatty alkylol amide condensates, oil soluble petroleum orvegetable oil sulfonates, or mixtures of these. Such agents will usuallycomprise up to about 5 weight percent of the total composition.

When the active ingredient is first mixed with a powdered carrier andsubsequently granulated, or pelleted, liquid non-ionic wetters can stillbe used, but it is usually preferably to incorporate at the mixing stageone of the solid, powdered anionic wetting agents such as thosepreviously listed for the 'wettable powders. Such agents will comprisefrom about 0 to 2 weight percent of the total composition.

Thus, the preferred granular pelleted formulations of this inventioncomprise about 5 to 30 weight percent active material, about 0 to 5weight percent wetting agent, and about 65 to '95 weight percent inertmineral carrier, as these terms are used herein.

Aqueous solutions: Certain compounds of this invention are soluble inmild acid or alkaline solutions and can be formulated and applied inaqueous solution in concentrations up to about The active agents of theinvention in formulations as just described may also contain a widevariety of other active ingredients necessary to carry out other aims asdesired. For example, they may contain algaecides, including quaternaryammonium salts, and copper sulfate; bactericides including quaternaryammonium salts and n-chlorosuccinimide; blossom thinners, includingphenols; defoliants, including phosphorotrithioates and chlorates;fumigants, including dithiocarbonates, cyanides and halogenated ethanes;fungicides including lime, sulfur, thiodiazines, phthalimides,sulfonamides, disulfides, benzoquinones, mercuric compounds, arsenates,cupric compounds, guanide salts, triazines, and phenylcrotonates;germicides including quaternary ammonium salts, phenolics, quaternarypyridinium salts, peracids, and formaldehyde; herbicides, includingsulfamates, borates, alpha haloacetamides, carbamates, substitutedphenoxy acids, substituted benzoic acids, halogenated aliphatic acidsand salts, substituted phenols, substituted ureas, phthalates,dithiocarbamates, thiolcarbamates, disulfides, chlorates, cyanates,xanthates, allyl alcohol, hexachloracetone, maleic hydrazide and phenylmercuric acetate; insecticides including natural products such aspyrethrin,

aresenicals and arsenites, benzoates, chlorinated hydrocarbons,phosphates, thiophosphates, phosphonates, thiazines, carbamates,terpenes, tartrates, and pyrrolidines; miticides including sulfonates,sulfites, sulfides, substituted phenols and salts, phosphonates,oxalates, sulphones, and strychinine; menatocides, including halogenatedpropanes and propenes, dithiocarbamates, and methyl bromide; insectrepellents including succinatcs, furfurals, ethylhexanediol and butylmesityl oxide; and rodenticides including coumarins, phosphorous, redsquill, fluorides, and arsenites.

The above described plant regulators may be used to both beneficiateplants and eradicate them. The destruction or beneficiation of theplants will be dependant, of course, upon the particular formulation,plant treated, dosage treatment, and other factors. In some instancesgrowth will be retarded. In other instances complete kill will beachieved.

It has been found here that the described compounds are active asherbicides to control and inhibit undesirable weed growth. The compoundsmay be used in the agricultural, industrial and domestic fields and maybe used to subject roadsides, embankments and other surfaces totreatment. The compounds are effective in inhibiting or destroying awide variety of grasses and weeds such as Johnson grass, bindweed, watergrass, orchard grass, smooth crabgrass, dwarf pea, soybean, quack grass,wheat, snapbean, nut grass, hairy crabgrass, curly dock, etc.

Representative compounds of the invention were then tested for theirherbicidal activity by treating a wide variety of plant species.

Specifically, a 5,000 p.p.m. stock was prepared by solubilizing 800 mg.of the test compound in 4 ml. of dimethylformamide. After obtaining thedimethylformamide solution or suspension, 12 ml. of analcoholic-surfactant mixture was added to end with a total of 16 ml.solution or suspension of the proper concentration. The activeherbicidal ingredient is then present at a 5% concentration. Thus, thesurfactant to active ratio is 0.51 v./w. which remains constant. Thefinal solution used in screening the herbicides for activity is made byadding 8 ml. of the above stock solution to 32 ml. of a 50:50 mixture ofacetone and deionized water. The final percentages of solvents andadjuvants are 5% dimethylformamide, 14.5% isopropyl alcohol, 40% water,40% acetone, and 0.5% surfactant. A typical surfactant used here is thecommercially available Tween 20.

The active compounds described here are adjusted for both pre-emergenceand post-emergence activity. The pro-emergence treatment andpost-emergence treatment dosages were both 10 lbs./ acre. In thepre-emergence test the soil was sprayed immediately after the seeds ofthe test plants were planted. The post-emergence treatment involvedspraying the already grown plants. The compounds were then rated forherbicidal response on a scale ranging from 0 to 10. A rating of 0indicates no visible response; a rating of 10 is a maximum response anda rating of l-9 indicates degrees of visible response between the twoextremes.

The following codes indicate how the plants responded to treatment. Acode rating of A indicates that the growth was accelerated, and therewas an increase in height of the plant over the control.

A rating of B indicates burn or contact injury. Essentially, thisindicates an acute response occurring within 72 hours after treatment. A5 rating indicates that the plant was half dead and a 10 indicatescomplete kill.

A code of C indicates chlorosis. 1-3 indicates increasing degrees ofchlorosis. 4-8 indicates increasing amounts of necrosis. A rating of 9with this code C indicates all the tissues are dead except for part ofthe stem. C10 indicates that plant was completely dead.

A code of D indicates defoliation. A rating of 5 for example, indicatesthat half the leaves had fallen.

A rating of E indicates that emergence was inhibited. A rating of S thenwould mean that only half the seedlings emerged.

A rating of F indicates earlier flowering. The numerical ratings alongwith the plant response key F would express relative degrees ofactivity.

The plant response key G indicates that growth was retarded. A rating ofwould mean that the plants were half the size of the controls. Thisresponse was used to point out compounds that retard growth with minimumvisual damage to the plant, e.g. compounds that burn the plant foliagewith subsequent retarded growth would be classified with B rating.

A code rating of H indicates a hormone effect. The hormone efiectsinclude epinasty, faciation, etc. The numerical rating indicates thedegree of activity.

The code rating I indicates albinism to necrosis to death. Thus, 1-3indicates an increasing degree of albinism. 4-8 indicates an increasingamount of necrosis. A rating of 9 with the code J indicates that all thetissue is dead except part of the stem and a rating of indicates thatthe plant was completely dead.

The code K is an indication of axillary stimulation. This indicatesaxillary bud growth on broad leaves and tillering on grasses.

The code L is an indication of leaf malformation not of the hormonaltype. P is used to indicate unusual pigmentation. The code S indicatestrue abscission.

The code letter T indicates selective burning of active growing tissuei.e. growing tips, axillary buds, etc. This burning also causes loss ofapical dominance in many cases.

Lastly, the code Y indicates a delay of emergence. The days of delayover control would determine the numerical rating given along with thecode letter Y.

The compounds of the invention were then tested and rated according toprocedures described above. The compounds were tested utilizing a widevariety of test plants, and it can be seen from the results below thatthe compounds of the invention show versatility in their herbicalactivity. In the results listed below the compound number refers to thesame example number. Thus, for example, compound No. 1 is the compoundof example number 1 and so forth.

TABLE III.2-CHLORO-3 PHENOXYMALEIMIDE Postemergence Johnson grass 1CBind weed 3C Water grass 1C Soy bean 10C Snap bean 1H, IOT Cotton 2H, 8CCommon foxtail 10 TABLE IV.2-CHLORO-3-METHOXYMALEIM1DE Post-emergence 12TABLE VII.-COM'POUND NO. v

Pre-emergence Bind weed 56 What is claimed is:

1. A maleimide derivative of the formula:

where -R is selected from the group consisting of hydrogen, and phenyl,R' is selected from the group consisting of hydrogen, halo andloweralkyl and R"' is selected from the group consisting of hydrogen,halo, lower alkylthio, and nitro.

3. A maleimide derivative of the formula:

wherein R is selected from the group consisting of alkyl containing 1-10carbon atoms, naphthyl, phenyl, substituted phenyl wherein said phenylsubstituent is selected from the group consisting of halo,loweralkylthio, loweralkyl and nitro, and benzyl, and R is selected fromthe group consisting of hydrogen, and phenyl.

4. The compound of claim 3 wherein R is phenyl and R is hydrogen.

5. The compound of claim 3 wherein R is methyl and R is hydrogen.

6. The compound of claim 3 where R and R' are phenyl.

7. The compound of claim 3 wherein R is 4-chlorophenyl and R is phenyl.

8. The compound of claim 3 wherein R is 3-chlorophenyl and R is phenyl.

9. The compound of claim 3 wherein R is beta-naphthyl and R is phenyl.

10. The compound of claim 3 wherein R is 2,4-dichlorophenyl and R isphenyl.

11. The compound of claim 3 wherein R is 4-methylthiophenyl and R isphenyl.

12. The compound of claim 3 wherein R is B-methyl, 4-methylthiopheny1and R is phenyl.

13. The compound of claim 3 wherein R is benzyl and R is phenyl.

13 14 14. The compound of the formula: 17. The compound of claim 14wherein R is 4-chlor0- phenyl. 0 18. The compound of claim 14 where R is3-chlorophenyl. 5 19. The compound of claim 14 where R is 4-methy1- Nthiophenyl. 20. The compound of claim 14 where R is 3-methy1,

4-methylthiophenyl.

21. The compound of claim 14 where R is 4-nitr0- 10 phenyl. h R 1 d itth h 1 References Cited w erein is se ecte om e group consisting of peny and substituted phenyl, wherein said phenyl substituent is UNITEDSTATES PATENTS selected from the group consisting of halo, loweralkyl-3,129,225 4/ 1964 Shaplm et a1 260-4473 thio, loweralkyl and nitro. 1

15. The compound of claim 14 where R is phenyl. 5 JOSEPH NARCAVAGEPnmary Exammer 16. The compound of claim 14 where R is Z-methyl, U.S.C1.X.R.

4chloropheny1. 7195; 260326.5 S

' 4 UNITED- STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,816,451 Dated Jllnell, 1974 lnventm-(s) Aldo Joseph Crovetti andDonald Murl Lynch It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

In Column 3 line 18, please add the following sentence, I

"The following examples illustrate typical compounds of the inventionand their method of preperationa" Signed end'sealed this 10th day' of'Decerllber :--374.

(SEAL fittest:

McCOY M. GIBSON JR. 0. P-LARSHALL DANN Attesting Officer Commissioner ofPatents FORM PO-IOSO (0-69) 1 UscoMMd-Dc 603766,, 0 0.54 aovlnmzwr "mumsornc: lsu 0-36I-38l

